# Electron traveling in air

1. May 30, 2012

### liquidFuzz

I'd like to calculate the likeliness of an electron jumping a gap of 100 to 200 nm. I have a source emitting electrons, the potential is 10 - 20 V. What is the proper way of calculate this?

$\displaystyle N = N_0 e ^{-???}$ where $N_0$ is the amount of emitted electrons. If I use this way, how do I determine the speed of the decline, in other words the exponent in the forumla?

2. May 30, 2012

### ZapperZ

Staff Emeritus
You may want to look up the mean free path of an electron in a STP air.

Note that the mean free path may also be dependent on the energy of the electrons.

Zz.